Genetic analysis and phylogenetic relationships of the Barb horse through the use of microsatellites

The aim of this study was to compare genetically Moroccan (MA) and Tunisian (TN) Barb horses and toe stablish the phylogenic relation between Barb horse and other horse breeds in Morocco by using microsatellites. First, 100 Moroccan barb and 100 Tunisian Barb horses were used. Genetic variability index between and inside the populations were estimated. 133 alleles were detected in the Moroccan population and 125 in the Tunisian. The mean number of alleles was 7.29 and 7.82 respectively for the Tunisian and Moroccan barb horse. The heterozygosity was almost similar in the two groups of Barb horses (TN = 0.716 and MA = 0.714). Fst was estimated at 0.0454 and 0.0780 respectively for TN and MA Barb horses. The Gst was also estimated at 0.012 and the Nei genetic distance at 0.05. The two populations are almost genetically similar and heterogeneous. Finally, 86,5 % of horses were correctly affected to their likelihood population. Secondly, 50 Arabian horses, 50 Arabian-Barb and 50 thoroughbreds and the 200 Barb horses previously studied were used to establish the phylogenic relationships. The use of 17 microsatellites showed that the Barb horses had specific alleles and the highest heterozygosity and the highest genetic distances were obtained with thoroughbred. The two Barb horse populations were highly combined in one side of the phylogenic tree

Analyse génétique et relations phylogénétiques du cheval Barbe par l’utilisation des microsatellites

The aim of this study was to compare genetically Moroccan (MA) and Tunisian (TN) Barb horses and toe stablish the phylogenic relation between Barb horse and other horse breeds in Morocco by using microsatellites. First, 100 Moroccan barb and 100 Tunisian Barb horses were used. Genetic variability index between and inside the populations were estimated. 133 alleles were detected in the Moroccan population and 125 in the Tunisian. The mean number of alleles was 7.29 and 7.82 respectively for the Tunisian and Moroccan barb horse. The heterozygosity was almost similar in the two groups of Barb horses (TN = 0.716 and MA = 0.714). Fst was estimated at 0.0454 and 0.0780 respectively for TN and MA Barb horses. The Gst was also estimated at 0.012 and the Nei genetic distance at 0.05. The two populations are almost genetically similar and heterogeneous. Finally, 86,5 % of horses were correctly affected to their likelihood population. Secondly, 50 Arabian horses, 50 Arabian-Barb and 50 thoroughbreds and the 200 Barb horses previously studied were used to establish the phylogenic relationships. The use of 17 microsatellites showed that the Barb horses had specific alleles and the highest heterozygosity and the highest genetic distances were obtained with thoroughbred. The two Barb horse populations were highly combined in one side of the phylogenic tree. Key words: horse, barb, genetic analysis, microsatellites, genetic index, phylogenic treeCe travail s’est intéressé à la comparaison génétique entre les chevaux Barbes du Maroc et de Tunisie et à l’établissement des relations phylogénétiques entre le cheval Barbe et les autres races de chevaux existantes au Maroc par l’utilisation des microsatellites. Premièrement, 100 chevaux barbes marocains et 100 tunisiens ont été utilisés et les indices de la variabilité intra et inter-population ont été évalués. 133 allèles ont été détectés pour le Barbe marocain contre 125 pour le tunisien. Le NMA était de 7,29 et 7,82 respectivement chez le Barbe tunisien et marocain. Les taux d’hétérozygotie moyens étaient presque similaires chez les deux populations. Le Fst était de 0,0454 et 0,0780 respectivement chez le Barbe de Tunisie et du Maroc. Le Gst était très faible et la distance génétique de Nei était de 0,05. Les deux populations sont donc hétérogènes et pratiquement identiques. 86,5% des individus étudiés ont été affecté convenablement à leur population d’origine. Deuxièmement, 50 chevaux Arabe, 50 Arabe-Barbe et 50 Pur-Sang, en plus des 200 chevaux Barbes préalablement étudiés ont été utilisés. Le cheval barbe a présenté des allèles spécifiques et une forte hétérozygotie avec une distance génétique maximale avec le Pur-Sang. L’arbre phylogénétique a montré, un regroupement très significatif entre les deux populations Barbes d’un côté et les trois autres races de l’autre. Mots clés : cheval, Barbe, analyse génétique, microsatellites, indices de variabilité génétique, arbre phylogénétiqu

Phosphorus diffusion gettering process of multicrystalline silicon using a sacrificial porous silicon layer

The aims of this work are to getter undesirable impurities from low-cost multicrystalline silicon (mc-Si) wafers and then enhance their electronic properties. We used an efficient process which consists of applying phosphorus diffusion into a sacrificial porous silicon (PS) layer in which the gettered impurities have been trapped after the heat treatment. As we have expected, after removing the phosphorus-rich PS layer, the electrical properties of the mc-Si wafers were significantly improved. The PS layers, realized on both sides of the mc-Si substrates, were formed by the stain-etching technique. The phosphorus treatment was achieved using a liquid POCl(3)-based source on both sides of the mc-Si wafers. The realized phosphorus/PS/Si/PS/phosphorus structures were annealed at a temperature ranging between 700°C and 950°C under a controlled O(2) atmosphere, which allows phosphorus to diffuse throughout the PS layers and to getter eventual metal impurities towards the phosphorus-doped PS layer. The effect of this gettering procedure was investigated by means of internal quantum efficiency and the dark current–voltage (I-V) characteristics. The minority carrier lifetime measurements were made using a WTC-120 photoconductance lifetime tester. The serial resistance and the shunt resistance carried out from the dark I-V curves confirm this gettering-related solar cell improvement. It has been shown that the photovoltaic parameters of the gettered silicon solar cells were improved with regard to the ungettered one, which proves the beneficial effect of this gettering process on the conversion efficiency of the multicrystalline silicon solar cells

Physical properties enhancement of porous silicon treated with In2O3 as a antireflective coating

In this work, we investigate the effect of Indium Oxide (In2O3) on the microstructural, optical, optoelectrical, and electrical properties of Porous Silicon (PS) layer. PS film was prepared by electrochemical anodization technique. In2O3 thin film was coated onto PS layer by using simple chemical immersion method. The investigation showed a significant enhancement in the optoelectronic property of PS coated with In2O3. The In2O3/PS layer was thermally annealed to improve the efficiency of the photovoltaic cells. Surface morphology and chemical composition modification of In2O3/PS were analyzed by atomic force microscopy (AFM) and Fourier transfer infrared (FTIR) spectroscopy. Optical reflectivity of sample In2O3/PS decreases significantly from 30% to 2.4% owing to an improvement in the light absorption. The optical parameters such as refractive index (n) and extinction coefficient (k), real and imaginary dielectric constants (ε1 & ε2), as well as the components percentage and thickness of samples were determined by analyzing the TanΨ and CosΔ ellipsometric parameters. Photoluminescence (PL) analysis of PS layer treated with In2O3 before and after annealing indicated a bleu emission shifts due to the quantum confinement effect of the oxidized silicon nanocrystals. Annealed PS coated In2O3 resulted a significant improvement in the minority carrier lifetime (τeff) from 2 to 16.4 μs. The optoelectronic and electronic quality of the treated PS layer with In2O3 was enhanced noticeably compared to the untreated porous layer, making it an ideal candidate for the solar cell applications. Keywords: Porous silicon, Indium oxide, Reflectivity, Photoluminescence, Spectroscopic ellipsometry, Lifetim

The study of the electronic structure of RuS2

In this study, through theoretical and experimental analyses, we demonstrated that unlike most semiconductors, RuS2 has different indirect bandgaps, which makes it a distinct energy conversion and storage device. In our experimental work, we used the chemical vapor transport and solvent evaporation methods. We obtained RuS2 at a low temperature of 800°C with different stoichiometric shifts of sulfur, such as RuS2.00,RuS1.96, andRuS1.90. Moreover, we studied the correlation between the band structure of RuS2 calculated using the linear muffin-tin orbitals-atomic sphere approximation (LMTO-ASA) method and the growth parameters for each sample. We obtained some noteworthy values of indirect bandgap, such as, 1.84,1.72,1.42,and1.25eV,and direct transition, such as, 2.04,1.93,1.77,and1.49eV. The bandgap values obtained by LMTO-ASA are.1.80727,1.69614,1.46743,and1.23522eV.We obtained indirect bandgaps and a direct transition at the gamma point; their values are 2.04,1.94,1.77, and 1.49eV. We found that RuS2 has valence and conduction bands. The gap energy evaluated by LMTO-ASA was close to the value of that obtained through experimental measurements. We showed that band energy is insensitive to the lattice constant, a. Bandgaps depend on the method of preparation because they change with the temperature and structure (ν). Similar results were obtained for the effective mass. We found two phonons at X and M points, as well as the probability of the existence of two indirect transitions to the bandgap. To the best of our knowledge, this is the first study to confirm that the position of sulfur and S–S distance significantly affect the bandgap

A new approach to produce porous silicon powder by chemical attack in phase vapor

The aim of this work was to investigate a simple and effective method to produce porous silicon from a powder of silicon. The preparation of porous silicon (PS) was realized by exposing silicon powders to acid vapor attack issued from acid solutions containing a 48% of HF and 65% of HNO3. The bond configuration of powder silicon before and after attack with acid vapor was monitored by Fourier transmission infrared spectroscopy (FTIR) and it was found that the PS was produced due to the newly formed Si-H bond during acid vapor attack. From the photoluminescence spectroscopy, it was shown that powder silicon attacked with acid vapor can lead to an increase of photoluminescence (PL) intensity when they are excited by light compared to untreated powder silicon and can provide blue shifts in the PL spectrum by increasing exposing time. This behavior may be attributed to the reduction in the size of the silicon, indicating consequently the formation of PS powder. The experimental results suggest a possibility that the chemical attack with acid vapor of the powder silicon provides a relatively easy way to produce porous silicon

Effect of acid vapor etching on morphological and opto-electric properties of flat silicon and silicon nanowire arrays: A comparative study

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